Osteoprotegerin protects endothelial cells against apoptotic cell death induced by Porphyromonas gingivalis cysteine proteinases
Osteoprotegerin protects endothelial cells against apoptotic cell death induced by Porphyromonas gingivalis cysteine proteinases
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DOI：
10.1111/j.1574-6968.2006.00458.x
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发表时间：
2006-11-01
影响因子：
2.1
通讯作者：
Chiba, Itsuo
中科院分区：
文献类型：
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作者：
Kobayashi-Sakamoto, Michiyo;Hirose, Kimiharu;Chiba, Itsuo
骨保护素（OPG）是牙周炎进展过程中破骨细胞生成的关键调节因子。最近的报道表明，骨保护素也可以防止动脉钙化，并有助于内皮细胞的存活。为了确定骨保护素的血管功能是否与牙周炎有关，我们研究了骨保护素是否有助于被牙龈卟啉单胞菌半胱氨酸蛋白酶（gingipains）损伤的内皮细胞的存活。牙龈蛋白酶可切割多种宿主蛋白，是导致成人牙周炎的主要病原菌牙龈假单胞菌的重要毒力因子。将人微血管内皮细胞（HMVEC）暴露于活化的牙龈蛋白酶提取物（P. gingivalis 381）中，并进行骨保护素预处理。四氮唑（WST-8）还原法测定细胞活力，Hoechst 33342核染色检测细胞凋亡。经活化的牙龈蛋白酶提取物处理16 h后，HMVEC几乎完全脱离组织培养皿，24 h时出现明显的细胞凋亡。骨保护素预处理HMVEC可降低细胞脱离程度和凋亡细胞死亡程度。结果表明，骨保护素预处理对牙龈活性细菌细胞提取物诱导的HMVEC脱离和凋亡细胞死亡具有保护作用。这些结果也提示骨保护素可能作为牙周炎期间内皮细胞的存活因子。
Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis during the progression of periodontitis. Recent reports suggest that osteoprotegerin may also prevent arterial calcification and contribute to endothelial cell survival. To determine whether the vascular functions of osteoprotegerin are involved in periodontitis, we examined whether osteoprotegerin contributed to the survival of endothelial cells damaged by Porphyromonas gingivalis cysteine proteinases (gingipains). Gingipain proteinases cleave a broad range of host proteins, and are important virulence factors of P. gingivalis, a major causative bacterium of adult periodontitis. Human microvascular endothelial cells (HMVEC) were exposed to activated gingipain extracts from P. gingivalis 381, with and without pretreatment with osteoprotegerin. Cell viability was quantified by the tetrazolium (WST-8) reduction assay, and apoptosis was examined using Hoechst 33342 nuclear staining. After 16 h of treatment with activated gingipain extracts, HMVEC showed near-complete detachment from the tissue culture dish, and apoptosis was evident by 24 h. Pretreatment of HMVEC with osteoprotegerin reduced the extent of both cellular detachment and apoptotic cell death. Our results indicated that osteoprotegerin pretreatment protected HMVEC against detachment and apoptotic cell death induced by gingipain-active bacterial cell extracts. These results also suggest that osteoprotegerin may function as a survival factor for endothelial cells during periodontitis.